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 1.19 2005/05/31 13:50:09 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>
70 * This version of Berkeley's rwhod has been modified to use IP multicast
71 * datagrams, under control of a new command-line option:
73 * rwhod -m causes rwhod to use IP multicast (instead of
74 * broadcast or unicast) on all interfaces that have
75 * the IFF_MULTICAST flag set in their "ifnet" structs
76 * (excluding the loopback interface). The multicast
77 * reports are sent with a time-to-live of 1, to prevent
78 * forwarding beyond the directly-connected subnet(s).
80 * rwhod -m <ttl> causes rwhod to send IP multicast datagrams with a
81 * time-to-live of <ttl>, via a SINGLE interface rather
82 * than all interfaces. <ttl> must be between 0 and
83 * MAX_MULTICAST_SCOPE, defined below. Note that "-m 1"
84 * is different than "-m", in that "-m 1" specifies
85 * transmission on one interface only.
87 * When "-m" is used without a <ttl> argument, the program accepts multicast
88 * rwhod reports from all multicast-capable interfaces. If a <ttl> argument
89 * is given, it accepts multicast reports from only one interface, the one
90 * on which reports are sent (which may be controlled via the host's routing
91 * table). Regardless of the "-m" option, the program accepts broadcast or
92 * unicast reports from all interfaces. Thus, this program will hear the
93 * reports of old, non-multicasting rwhods, but, if multicasting is used,
94 * those old rwhods won't hear the reports generated by this program.
96 * -- Steve Deering, Stanford University, February 1989
99 #define UNPRIV_USER "daemon"
100 #define UNPRIV_GROUP "daemon"
102 #define WITH_ERRNO 1 /* Write to syslog with errno (%m) */
103 #define WITHOUT_ERRNO 0 /* Write to syslog without errno */
105 #define NO_MULTICAST 0 /* multicast modes */
106 #define PER_INTERFACE_MULTICAST 1
107 #define SCOPED_MULTICAST 2
109 #define MAX_MULTICAST_SCOPE 32 /* "site-wide", by convention */
111 #define INADDR_WHOD_GROUP (u_long)0xe0000103 /* 224.0.1.3 */
112 /* (belongs in protocols/rwhod.h) */
116 int iff_flag = IFF_POINTOPOINT;
117 int multicast_mode = NO_MULTICAST;
119 struct sockaddr_in multicast_addr;
122 * Alarm interval. Don't forget to change the down time check in ruptime
123 * if this is changed.
125 #define AL_INTERVAL (3 * 60)
127 char myname[MAXHOSTNAMELEN];
130 * We communicate with each neighbor in a list constructed at the time we're
131 * started up. Neighbors are currently directly connected via a hardware
135 struct neighbor *n_next;
136 char *n_name; /* interface name */
137 struct sockaddr *n_addr; /* who to send to */
138 int n_addrlen; /* size of address */
139 int n_flags; /* should forward?, interface flags */
142 struct neighbor *neighbors;
146 volatile sig_atomic_t got_sigalrm, got_sighup;
148 #define WHDRSIZE (sizeof(mywd) - sizeof(mywd.wd_we))
150 void run_as(uid_t *, gid_t *);
152 void getboottime(void);
155 void quit(const char *, int);
156 void rt_xaddrs(caddr_t, caddr_t, struct rt_addrinfo *);
157 int verify(char *, int);
158 static void usage(void);
161 char *interval(int, const char *);
162 ssize_t Sendto(int, const void *, size_t, int,
163 const struct sockaddr *, int);
165 #define Sendto sendto
169 main(int argc, char *argv[])
171 struct sockaddr_in from;
173 char path[64], *ep, *cp;
175 struct sockaddr_in m_sin;
181 errx(1, "not super user");
183 run_as(&unpriv_uid, &unpriv_gid);
186 while (argc > 0 && *argv[0] == '-') {
187 if (strcmp(*argv, "-m") == 0) {
188 if (argc > 1 && *(argv + 1)[0] != '-') {
189 /* Argument has been given */
191 multicast_mode = SCOPED_MULTICAST;
192 tmp = strtol(*argv, &ep, 10);
193 if (*ep != '\0' || tmp < INT_MIN || tmp > INT_MAX)
194 errx(1, "invalid ttl: %s", *argv);
195 multicast_scope = (int)tmp;
196 if (multicast_scope > MAX_MULTICAST_SCOPE)
197 errx(1, "ttl must not exceed %u",
198 MAX_MULTICAST_SCOPE);
200 else multicast_mode = PER_INTERFACE_MULTICAST;
202 else if (strcmp(*argv, "-i") == 0)
204 else if (strcmp(*argv, "-l") == 0)
206 else if (strcmp(*argv, "-p") == 0)
216 pidfile(getprogname());
218 signal(SIGHUP, onsignal);
219 openlog("rwhod", LOG_PID, LOG_DAEMON);
220 sp = getservbyname("who", "udp");
222 quit("udp/who: unknown service", WITHOUT_ERRNO);
224 if (chdir(_PATH_RWHODIR) < 0)
225 quit(_PATH_RWHODIR, WITH_ERRNO);
228 * Establish host name as returned by system.
230 if (gethostname(myname, sizeof(myname)) < 0)
231 quit("gethostname", WITH_ERRNO);
233 if ((cp = strchr(myname, '.')) != NULL)
235 strlcpy(mywd.wd_hostname, myname, sizeof(mywd.wd_hostname));
236 utmpf = open(_PATH_UTMP, O_RDONLY|O_CREAT, 0644);
238 quit(_PATH_UTMP, WITH_ERRNO);
241 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
242 quit("socket", WITH_ERRNO);
244 if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0)
245 quit("setsockopt SO_BROADCAST", WITH_ERRNO);
247 memset(&m_sin, 0, sizeof(m_sin));
248 m_sin.sin_len = sizeof(m_sin);
249 m_sin.sin_family = AF_INET;
250 m_sin.sin_port = sp->s_port;
251 if (bind(s, (struct sockaddr *)&m_sin, sizeof(m_sin)) < 0)
252 quit("bind", WITH_ERRNO);
255 setgroups(1, &unpriv_gid); /* XXX BOGUS groups[0] = egid */
260 signal(SIGALRM, onsignal);
266 socklen_t len = sizeof(from);
268 if (got_sigalrm == 1) {
272 else if (got_sighup == 1) {
277 cc = recvfrom(s, (char *)&wd, sizeof(struct whod), 0,
278 (struct sockaddr *)&from, &len);
282 if (errno == EINTR) {
283 if (got_sigalrm == 1) {
287 else if (got_sighup == 1) {
292 syslog(LOG_WARNING, "recv: %m");
296 if (from.sin_port != sp->s_port && !insecure_mode) {
297 syslog(LOG_WARNING, "%d: bad source port from %s",
298 ntohs(from.sin_port), inet_ntoa(from.sin_addr));
301 if (cc < (int)WHDRSIZE) {
302 syslog(LOG_WARNING, "short packet from %s",
303 inet_ntoa(from.sin_addr));
306 if (wd.wd_vers != WHODVERSION)
308 if (wd.wd_type != WHODTYPE_STATUS)
310 if (!verify(wd.wd_hostname, sizeof wd.wd_hostname)) {
311 syslog(LOG_WARNING, "malformed host name from %s",
312 inet_ntoa(from.sin_addr));
315 snprintf(path, sizeof path, "whod.%s", wd.wd_hostname);
317 * Rather than truncating and growing the file each time,
318 * use ftruncate if size is less than previous size.
320 whod = open(path, O_WRONLY | O_CREAT, 0644);
322 syslog(LOG_WARNING, "%s: %m", path);
325 #if ENDIAN != BIG_ENDIAN
327 int i, n = (cc - WHDRSIZE)/sizeof(struct whoent);
330 /* undo header byte swapping before writing to file */
331 wd.wd_sendtime = ntohl(wd.wd_sendtime);
332 for (i = 0; i < 3; i++)
333 wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]);
334 wd.wd_boottime = ntohl(wd.wd_boottime);
336 for (i = 0; i < n; i++) {
337 we->we_idle = ntohl(we->we_idle);
338 we->we_utmp.out_time =
339 ntohl(we->we_utmp.out_time);
344 time((time_t *)&wd.wd_recvtime);
345 write(whod, (char *)&wd, cc);
346 if (fstat(whod, &st) < 0 || st.st_size > cc)
355 fprintf(stderr, "usage: rwhod [-i] [-p] [-l] [-m [ttl]]\n");
360 run_as(uid_t *uid, gid_t *gid)
365 pw = getpwnam(UNPRIV_USER);
367 quit("getpwnam(daemon)", WITH_ERRNO);
371 gr = getgrnam(UNPRIV_GROUP);
373 quit("getgrnam(daemon)", WITH_ERRNO);
379 * Check out host name for unprintables
380 * and other funnies before allowing a file
381 * to be created. Sorry, but blanks aren't allowed.
384 verify(char *name, int maxlen)
388 while (*name && size < maxlen - 1) {
389 if (!isascii(*name) || !(isalnum(*name) || ispunct(*name)))
400 if (signo == SIGALRM)
416 struct whoent *we = mywd.wd_we, *wlast;
424 if (alarmcount % 10 == 0)
428 if ((stb.st_mtime != utmptime) || (stb.st_size > utmpsize)) {
429 utmptime = stb.st_mtime;
430 if (stb.st_size > utmpsize) {
431 utmpsize = stb.st_size + 10 * sizeof(struct utmp);
432 utmp = reallocf(utmp, utmpsize);
434 syslog(LOG_WARNING, "malloc failed: %m");
439 lseek(utmpf, (off_t)0, L_SET);
440 cc = read(utmpf, (char *)utmp, stb.st_size);
442 syslog(LOG_ERR, "read(%s): %m", _PATH_UTMP);
445 wlast = &mywd.wd_we[1024 / sizeof(struct whoent) - 1];
446 utmpent = cc / sizeof(struct utmp);
447 for (i = 0; i < utmpent; i++)
448 if (utmp[i].ut_name[0]) {
449 memcpy(we->we_utmp.out_line, utmp[i].ut_line,
450 sizeof(utmp[i].ut_line));
451 memcpy(we->we_utmp.out_name, utmp[i].ut_name,
452 sizeof(utmp[i].ut_name));
453 we->we_utmp.out_time = htonl(utmp[i].ut_time);
458 utmpent = we - mywd.wd_we;
462 * The test on utmpent looks silly---after all, if no one is
463 * logged on, why worry about efficiency?---but is useful on
464 * (e.g.) compute servers.
466 if (utmpent && chdir(_PATH_DEV)) {
467 syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
472 for (i = 0; i < utmpent; i++) {
473 if (stat(we->we_utmp.out_line, &stb) >= 0)
474 we->we_idle = htonl(now - stb.st_atime);
477 getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0]));
478 for (i = 0; i < 3; i++)
479 mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
480 cc = (char *)we - (char *)&mywd;
481 mywd.wd_sendtime = htonl(time(0));
482 mywd.wd_vers = WHODVERSION;
483 mywd.wd_type = WHODTYPE_STATUS;
484 if (multicast_mode == SCOPED_MULTICAST) {
485 Sendto(s, (char *)&mywd, cc, 0,
486 (struct sockaddr *)&multicast_addr,
487 sizeof(multicast_addr));
489 else for (np = neighbors; np != NULL; np = np->n_next) {
490 if (multicast_mode == PER_INTERFACE_MULTICAST &&
491 np->n_flags & IFF_MULTICAST) {
493 * Select the outgoing interface for the multicast.
495 if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF,
496 &(((struct sockaddr_in *)np->n_addr)->sin_addr),
497 sizeof(struct in_addr)) < 0) {
498 quit("setsockopt IP_MULTICAST_IF", WITH_ERRNO);
500 Sendto(s, (char *)&mywd, cc, 0,
501 (struct sockaddr *)&multicast_addr,
502 sizeof(multicast_addr));
503 } else Sendto(s, (char *)&mywd, cc, 0,
504 np->n_addr, np->n_addrlen);
506 if (utmpent && chdir(_PATH_RWHODIR)) {
507 syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
522 mib[1] = KERN_BOOTTIME;
524 if (sysctl(mib, 2, &tm, &size, NULL, 0) == -1)
525 quit("cannot get boottime", WITH_ERRNO);
527 mywd.wd_boottime = htonl(tm.tv_sec);
531 * If wrterrno == WITH_ERRNO, we will print
532 * errno. If not, we leave errno out.
535 quit(const char *msg, int wrterrno)
538 syslog(LOG_ERR, "%s: %m", msg);
540 syslog(LOG_ERR, "%s", msg);
545 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
546 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
549 rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo)
554 memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
555 for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
556 if ((rtinfo->rti_addrs & (1 << i)) == 0)
558 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
564 * Figure out device configuration and select
565 * networks which deserve status information.
568 configure(int c_sock)
571 struct if_msghdr *ifm;
572 struct ifa_msghdr *ifam;
573 struct sockaddr_dl *sdl;
575 int mib[6], flags = 0, len;
576 char *buf, *lim, *next;
577 struct rt_addrinfo info;
579 if (multicast_mode != NO_MULTICAST) {
580 multicast_addr.sin_len = sizeof(multicast_addr);
581 multicast_addr.sin_family = AF_INET;
582 multicast_addr.sin_addr.s_addr = htonl(INADDR_WHOD_GROUP);
583 multicast_addr.sin_port = sp->s_port;
586 if (multicast_mode == SCOPED_MULTICAST) {
590 mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
591 mreq.imr_interface.s_addr = htonl(INADDR_ANY);
592 if (setsockopt(c_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
593 &mreq, sizeof(mreq)) < 0) {
595 "setsockopt IP_ADD_MEMBERSHIP: %m");
598 ttl = multicast_scope;
599 if (setsockopt(c_sock, IPPROTO_IP, IP_MULTICAST_TTL,
600 &ttl, sizeof(ttl)) < 0) {
602 "setsockopt IP_MULTICAST_TTL: %m");
612 mib[4] = NET_RT_IFLIST;
614 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
615 quit("route-sysctl-estimate", WITH_ERRNO);
616 if ((buf = malloc(needed)) == NULL)
617 quit("malloc", WITH_ERRNO);
618 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
619 quit("actual retrieval of interface table", WITH_ERRNO);
622 sdl = NULL; /* XXX just to keep gcc -Wall happy */
623 for (next = buf; next < lim; next += ifm->ifm_msglen) {
624 ifm = (struct if_msghdr *)next;
625 if (ifm->ifm_type == RTM_IFINFO) {
626 sdl = (struct sockaddr_dl *)(ifm + 1);
627 flags = ifm->ifm_flags;
630 if ((flags & IFF_UP) == 0 ||
631 (flags & (((multicast_mode == PER_INTERFACE_MULTICAST) ?
633 IFF_BROADCAST|iff_flag)) == 0)
635 if (ifm->ifm_type != RTM_NEWADDR)
636 quit("out of sync parsing NET_RT_IFLIST", WITHOUT_ERRNO);
637 ifam = (struct ifa_msghdr *)ifm;
638 info.rti_addrs = ifam->ifam_addrs;
639 rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam,
641 /* gag, wish we could get rid of Internet dependencies */
642 #define dstaddr info.rti_info[RTAX_BRD]
643 #define ifaddr info.rti_info[RTAX_IFA]
644 #define IPADDR_SA(x) ((struct sockaddr_in *)(x))->sin_addr.s_addr
645 #define PORT_SA(x) ((struct sockaddr_in *)(x))->sin_port
646 if (dstaddr == 0 || dstaddr->sa_family != AF_INET)
648 PORT_SA(dstaddr) = sp->s_port;
649 for (np = neighbors; np != NULL; np = np->n_next)
650 if (memcmp(sdl->sdl_data, np->n_name,
651 sdl->sdl_nlen) == 0 &&
652 IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr))
656 len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1;
657 np = (struct neighbor *)malloc(len);
659 quit("malloc of neighbor structure", WITH_ERRNO);
662 np->n_addr = (struct sockaddr *)(np + 1);
663 np->n_addrlen = dstaddr->sa_len;
664 np->n_name = np->n_addrlen + (char *)np->n_addr;
665 memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen);
666 memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen);
667 if (multicast_mode == PER_INTERFACE_MULTICAST &&
668 (flags & IFF_MULTICAST) &&
669 !(flags & IFF_LOOPBACK)) {
672 memcpy((char *)np->n_addr, (char *)ifaddr,
674 mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
675 mreq.imr_interface.s_addr =
676 ((struct sockaddr_in *)np->n_addr)->sin_addr.s_addr;
677 if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP,
678 &mreq, sizeof(mreq)) < 0) {
680 "setsockopt IP_ADD_MEMBERSHIP: %m");
682 /* Fall back to broadcast on this if. */
683 np->n_flags &= ~IFF_MULTICAST;
690 np->n_next = neighbors;
699 Sendto(int s_debug, const void *buf, size_t cc, int flags,
700 const struct sockaddr *to, int tolen)
702 const struct whod *w = (const struct whod *)buf;
703 const struct whoent *we;
704 const struct sockaddr_in *sock_in = (const struct sockaddr_in *)to;
708 ret = sendto(s_debug, buf, cc, flags, to, tolen);
710 printf("sendto %x.%d\n", ntohl(sock_in->sin_addr.s_addr),
711 ntohs(sock_in->sin_port));
712 printf("hostname %s %s\n", w->wd_hostname,
713 interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), " up"));
714 printf("load %4.2f, %4.2f, %4.2f\n",
715 ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0,
716 ntohl(w->wd_loadav[2]) / 100.0);
718 for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0; cc--, we++) {
719 time_t t = ntohl(we->we_utmp.out_time);
720 idle_time = we->we_idle;
721 printf("%-8.8s %s:%s %.12s",
722 we->we_utmp.out_name,
723 w->wd_hostname, we->we_utmp.out_line,
725 idle_time = ntohl(we->we_idle) / 60;
727 if (idle_time >= 100*60)
728 idle_time = 100*60 - 1;
730 printf(" %2d", idle_time / 60);
733 printf(":%02d", idle_time % 60);
741 interval(int inter_time, const char *updown)
743 static char resbuf[32];
744 int days, hours, minutes;
746 if (inter_time < 0 || inter_time > 3*30*24*60*60) {
747 snprintf(resbuf, sizeof(resbuf), " %s ??:??", updown);
750 minutes = (inter_time + 59) / 60; /* round to minutes */
751 hours = minutes / 60; minutes %= 60;
752 days = hours / 24; hours %= 24;
754 snprintf(resbuf, sizeof(resbuf), "%s %2d+%02d:%02d",
755 updown, days, hours, minutes);
757 snprintf(resbuf, sizeof(resbuf), "%s %2d:%02d",
758 updown, hours, minutes);