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 1.23 2005/07/01 13:13:00 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>
71 * This version of Berkeley's rwhod has been modified to use IP multicast
72 * datagrams, under control of a new command-line option:
74 * rwhod -m causes rwhod to use IP multicast (instead of
75 * broadcast or unicast) on all interfaces that have
76 * the IFF_MULTICAST flag set in their "ifnet" structs
77 * (excluding the loopback interface). The multicast
78 * reports are sent with a time-to-live of 1, to prevent
79 * forwarding beyond the directly-connected subnet(s).
81 * rwhod -m <ttl> causes rwhod to send IP multicast datagrams with a
82 * time-to-live of <ttl>, via a SINGLE interface rather
83 * than all interfaces. <ttl> must be between 0 and
84 * MAX_MULTICAST_SCOPE, defined below. Note that "-m 1"
85 * is different than "-m", in that "-m 1" specifies
86 * transmission on one interface only.
88 * When "-m" is used without a <ttl> argument, the program accepts multicast
89 * rwhod reports from all multicast-capable interfaces. If a <ttl> argument
90 * is given, it accepts multicast reports from only one interface, the one
91 * on which reports are sent (which may be controlled via the host's routing
92 * table). Regardless of the "-m" option, the program accepts broadcast or
93 * unicast reports from all interfaces. Thus, this program will hear the
94 * reports of old, non-multicasting rwhods, but, if multicasting is used,
95 * those old rwhods won't hear the reports generated by this program.
97 * -- Steve Deering, Stanford University, February 1989
100 #define UNPRIV_USER "daemon"
101 #define UNPRIV_GROUP "daemon"
103 #define WITH_ERRNO 1 /* Write to syslog with errno (%m) */
104 #define WITHOUT_ERRNO 0 /* Write to syslog without errno */
106 #define NO_MULTICAST 0 /* multicast modes */
107 #define PER_INTERFACE_MULTICAST 1
108 #define SCOPED_MULTICAST 2
110 #define MAX_MULTICAST_SCOPE 32 /* "site-wide", by convention */
112 #define INADDR_WHOD_GROUP (u_long)0xe0000103 /* 224.0.1.3 */
113 /* (belongs in protocols/rwhod.h) */
117 int iff_flag = IFF_POINTOPOINT;
118 int multicast_mode = NO_MULTICAST;
120 struct sockaddr_in multicast_addr;
122 char myname[MAXHOSTNAMELEN];
125 * We communicate with each neighbor in a list constructed at the time we're
126 * started up. Neighbors are currently directly connected via a hardware
130 struct neighbor *n_next;
131 char *n_name; /* interface name */
132 struct sockaddr *n_addr; /* who to send to */
133 int n_addrlen; /* size of address */
134 int n_flags; /* should forward?, interface flags */
137 struct neighbor *neighbors;
141 volatile sig_atomic_t onsighup;
143 #define WHDRSIZE (sizeof(mywd) - sizeof(mywd.wd_we))
145 void run_as(uid_t *, gid_t *);
147 void getboottime(void);
148 void send_host_information(void);
150 void quit(const char *, int);
151 void rt_xaddrs(caddr_t, caddr_t, struct rt_addrinfo *);
152 int verify(char *, int);
153 void handleread(int);
154 static void usage(void);
155 void timeadd(struct timeval *, time_t, struct timeval *);
158 char *interval(int, const char *);
159 ssize_t Sendto(int, const void *, size_t, int,
160 const struct sockaddr *, int);
162 #define Sendto sendto
166 main(int argc, char *argv[])
168 struct pollfd pfd[1];
171 int send_time = 180; /* Default time, 180 seconds (3 minutes) */
172 struct sockaddr_in m_sin;
177 struct timeval next, now;
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;
200 } else if (strcmp(*argv, "-g") == 0) {
201 if (argc > 1 && *(argv + 1)[0] != '-') {
203 send_time = (int)strtol(*argv, &ep, 10);
205 errx(1, "time must be greater than 0");
209 errx(1, "invalid argument: %s", *argv);
210 if (*ep == 'M' || *ep == 'm') {
211 /* Time in minutes. */
214 errx(1, "invalid argument: %s", *argv);
218 errx(1, "cannot be greater than 180 seconds (3 minutes)");
220 errx(1, "missing argument");
221 } else if (strcmp(*argv, "-i") == 0)
223 else if (strcmp(*argv, "-l") == 0)
225 else if (strcmp(*argv, "-p") == 0)
235 pidfile(getprogname());
238 openlog("rwhod", LOG_PID, LOG_DAEMON);
239 sp = getservbyname("who", "udp");
241 quit("udp/who: unknown service", WITHOUT_ERRNO);
243 if (chdir(_PATH_RWHODIR) < 0)
244 quit(_PATH_RWHODIR, WITH_ERRNO);
247 * Establish host name as returned by system.
249 if (gethostname(myname, sizeof(myname)) < 0)
250 quit("gethostname", WITH_ERRNO);
252 if ((cp = strchr(myname, '.')) != NULL)
254 strlcpy(mywd.wd_hostname, myname, sizeof(mywd.wd_hostname));
255 utmpf = open(_PATH_UTMP, O_RDONLY|O_CREAT, 0644);
257 quit(_PATH_UTMP, WITH_ERRNO);
260 if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
261 quit("socket", WITH_ERRNO);
263 if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0)
264 quit("setsockopt SO_BROADCAST", WITH_ERRNO);
266 memset(&m_sin, 0, sizeof(m_sin));
267 m_sin.sin_len = sizeof(m_sin);
268 m_sin.sin_family = AF_INET;
269 m_sin.sin_port = sp->s_port;
270 if (bind(s, (struct sockaddr *)&m_sin, sizeof(m_sin)) < 0)
271 quit("bind", WITH_ERRNO);
274 setgroups(1, &unpriv_gid); /* XXX BOGUS groups[0] = egid */
280 send_host_information();
282 gettimeofday(&now, NULL);
283 timeadd(&now, delta, &next);
287 pfd[0].events = POLLIN;
292 n = poll(pfd, 1, 1000);
302 gettimeofday(&now, NULL);
303 if (now.tv_sec > next.tv_sec) {
304 send_host_information();
305 timeadd(&now, delta, &next);
312 timeadd(struct timeval *now, time_t delta, struct timeval *next)
314 (next)->tv_sec = (now)->tv_sec + delta;
320 struct sockaddr_in from;
325 socklen_t len = sizeof(from);
327 cc = recvfrom(sock, (char *)&wd, sizeof(struct whod), 0,
328 (struct sockaddr *)&from, &len);
332 if (cc < 0 && errno != EINTR) {
333 syslog(LOG_WARNING, "recv: %m");
337 if (from.sin_port != sp->s_port && !insecure_mode) {
338 syslog(LOG_WARNING, "%d: bad source port from %s",
339 ntohs(from.sin_port), inet_ntoa(from.sin_addr));
342 if (cc < (int)WHDRSIZE) {
343 syslog(LOG_WARNING, "short packet from %s",
344 inet_ntoa(from.sin_addr));
347 if (wd.wd_vers != WHODVERSION)
349 if (wd.wd_type != WHODTYPE_STATUS)
351 if (!verify(wd.wd_hostname, sizeof wd.wd_hostname)) {
352 syslog(LOG_WARNING, "malformed host name from %s",
353 inet_ntoa(from.sin_addr));
356 snprintf(path, sizeof path, "whod.%s", wd.wd_hostname);
358 * Rather than truncating and growing the file each time,
359 * use ftruncate if size is less than previous size.
361 whod = open(path, O_WRONLY | O_CREAT, 0644);
363 syslog(LOG_WARNING, "%s: %m", path);
366 #if ENDIAN != BIG_ENDIAN
368 int i, n = (cc - WHDRSIZE)/sizeof(struct whoent);
371 /* undo header byte swapping before writing to file */
372 wd.wd_sendtime = ntohl(wd.wd_sendtime);
373 for (i = 0; i < 3; i++)
374 wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]);
375 wd.wd_boottime = ntohl(wd.wd_boottime);
377 for (i = 0; i < n; i++) {
378 we->we_idle = ntohl(we->we_idle);
379 we->we_utmp.out_time =
380 ntohl(we->we_utmp.out_time);
385 time((time_t *)&wd.wd_recvtime);
386 write(whod, (char *)&wd, cc);
387 if (fstat(whod, &st) < 0 || st.st_size > cc)
395 fprintf(stderr, "usage: rwhod [-i] [-p] [-l] [-m [ttl]]\n");
400 hup(int signo __unused)
406 run_as(uid_t *uid, gid_t *gid)
411 pw = getpwnam(UNPRIV_USER);
413 quit("getpwnam(daemon)", WITH_ERRNO);
417 gr = getgrnam(UNPRIV_GROUP);
419 quit("getgrnam(daemon)", WITH_ERRNO);
425 * Check out host name for unprintables
426 * and other funnies before allowing a file
427 * to be created. Sorry, but blanks aren't allowed.
430 verify(char *name, int maxlen)
434 while (*name && size < maxlen - 1) {
435 if (!isascii(*name) || !(isalnum(*name) || ispunct(*name)))
450 send_host_information(void)
453 struct whoent *we = mywd.wd_we, *wlast;
461 if (alarmcount % 10 == 0)
465 if ((stb.st_mtime != utmptime) || (stb.st_size > utmpsize)) {
466 utmptime = stb.st_mtime;
467 if (stb.st_size > utmpsize) {
468 utmpsize = stb.st_size + 10 * sizeof(struct utmp);
469 utmp = reallocf(utmp, utmpsize);
471 syslog(LOG_WARNING, "malloc failed: %m");
476 lseek(utmpf, (off_t)0, L_SET);
477 cc = read(utmpf, (char *)utmp, stb.st_size);
479 syslog(LOG_ERR, "read(%s): %m", _PATH_UTMP);
482 wlast = &mywd.wd_we[1024 / sizeof(struct whoent) - 1];
483 utmpent = cc / sizeof(struct utmp);
484 for (i = 0; i < utmpent; i++)
485 if (utmp[i].ut_name[0]) {
486 memcpy(we->we_utmp.out_line, utmp[i].ut_line,
487 sizeof(utmp[i].ut_line));
488 memcpy(we->we_utmp.out_name, utmp[i].ut_name,
489 sizeof(utmp[i].ut_name));
490 we->we_utmp.out_time = htonl(utmp[i].ut_time);
495 utmpent = we - mywd.wd_we;
499 * The test on utmpent looks silly---after all, if no one is
500 * logged on, why worry about efficiency?---but is useful on
501 * (e.g.) compute servers.
503 if (utmpent && chdir(_PATH_DEV)) {
504 syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
509 for (i = 0; i < utmpent; i++) {
510 if (stat(we->we_utmp.out_line, &stb) >= 0)
511 we->we_idle = htonl(now - stb.st_atime);
514 getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0]));
515 for (i = 0; i < 3; i++)
516 mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
517 cc = (char *)we - (char *)&mywd;
518 mywd.wd_sendtime = htonl(time(0));
519 mywd.wd_vers = WHODVERSION;
520 mywd.wd_type = WHODTYPE_STATUS;
521 if (multicast_mode == SCOPED_MULTICAST) {
522 Sendto(s, (char *)&mywd, cc, 0,
523 (struct sockaddr *)&multicast_addr,
524 sizeof(multicast_addr));
526 else for (np = neighbors; np != NULL; np = np->n_next) {
527 if (multicast_mode == PER_INTERFACE_MULTICAST &&
528 np->n_flags & IFF_MULTICAST) {
530 * Select the outgoing interface for the multicast.
532 if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF,
533 &(((struct sockaddr_in *)np->n_addr)->sin_addr),
534 sizeof(struct in_addr)) < 0) {
535 quit("setsockopt IP_MULTICAST_IF", WITH_ERRNO);
537 Sendto(s, (char *)&mywd, cc, 0,
538 (struct sockaddr *)&multicast_addr,
539 sizeof(multicast_addr));
540 } else Sendto(s, (char *)&mywd, cc, 0,
541 np->n_addr, np->n_addrlen);
543 if (utmpent && chdir(_PATH_RWHODIR)) {
544 syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
557 mib[1] = KERN_BOOTTIME;
559 if (sysctl(mib, 2, &tm, &size, NULL, 0) == -1)
560 quit("cannot get boottime", WITH_ERRNO);
562 mywd.wd_boottime = htonl(tm.tv_sec);
566 * If wrterrno == WITH_ERRNO, we will print
567 * errno. If not, we leave errno out.
570 quit(const char *msg, int wrterrno)
573 syslog(LOG_ERR, "%s: %m", msg);
575 syslog(LOG_ERR, "%s", msg);
580 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
581 #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len))
584 rt_xaddrs(caddr_t cp, caddr_t cplim, struct rt_addrinfo *rtinfo)
589 memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info));
590 for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) {
591 if ((rtinfo->rti_addrs & (1 << i)) == 0)
593 rtinfo->rti_info[i] = sa = (struct sockaddr *)cp;
599 * Figure out device configuration and select
600 * networks which deserve status information.
603 configure(int c_sock)
606 struct if_msghdr *ifm;
607 struct ifa_msghdr *ifam;
608 struct sockaddr_dl *sdl;
610 int mib[6], flags = 0, len;
611 char *buf, *lim, *next;
612 struct rt_addrinfo info;
614 if (multicast_mode != NO_MULTICAST) {
615 multicast_addr.sin_len = sizeof(multicast_addr);
616 multicast_addr.sin_family = AF_INET;
617 multicast_addr.sin_addr.s_addr = htonl(INADDR_WHOD_GROUP);
618 multicast_addr.sin_port = sp->s_port;
621 if (multicast_mode == SCOPED_MULTICAST) {
625 mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
626 mreq.imr_interface.s_addr = htonl(INADDR_ANY);
627 if (setsockopt(c_sock, IPPROTO_IP, IP_ADD_MEMBERSHIP,
628 &mreq, sizeof(mreq)) < 0) {
630 "setsockopt IP_ADD_MEMBERSHIP: %m");
633 ttl = multicast_scope;
634 if (setsockopt(c_sock, IPPROTO_IP, IP_MULTICAST_TTL,
635 &ttl, sizeof(ttl)) < 0) {
637 "setsockopt IP_MULTICAST_TTL: %m");
647 mib[4] = NET_RT_IFLIST;
649 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0)
650 quit("route-sysctl-estimate", WITH_ERRNO);
651 if ((buf = malloc(needed)) == NULL)
652 quit("malloc", WITH_ERRNO);
653 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0)
654 quit("actual retrieval of interface table", WITH_ERRNO);
657 sdl = NULL; /* XXX just to keep gcc -Wall happy */
658 for (next = buf; next < lim; next += ifm->ifm_msglen) {
659 ifm = (struct if_msghdr *)next;
660 if (ifm->ifm_type == RTM_IFINFO) {
661 sdl = (struct sockaddr_dl *)(ifm + 1);
662 flags = ifm->ifm_flags;
665 if ((flags & IFF_UP) == 0 ||
666 (flags & (((multicast_mode == PER_INTERFACE_MULTICAST) ?
668 IFF_BROADCAST|iff_flag)) == 0)
670 if (ifm->ifm_type != RTM_NEWADDR)
671 quit("out of sync parsing NET_RT_IFLIST", WITHOUT_ERRNO);
672 ifam = (struct ifa_msghdr *)ifm;
673 info.rti_addrs = ifam->ifam_addrs;
674 rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam,
676 /* gag, wish we could get rid of Internet dependencies */
677 #define dstaddr info.rti_info[RTAX_BRD]
678 #define ifaddr info.rti_info[RTAX_IFA]
679 #define IPADDR_SA(x) ((struct sockaddr_in *)(x))->sin_addr.s_addr
680 #define PORT_SA(x) ((struct sockaddr_in *)(x))->sin_port
681 if (dstaddr == 0 || dstaddr->sa_family != AF_INET)
683 PORT_SA(dstaddr) = sp->s_port;
684 for (np = neighbors; np != NULL; np = np->n_next)
685 if (memcmp(sdl->sdl_data, np->n_name,
686 sdl->sdl_nlen) == 0 &&
687 IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr))
691 len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1;
692 np = (struct neighbor *)malloc(len);
694 quit("malloc of neighbor structure", WITH_ERRNO);
697 np->n_addr = (struct sockaddr *)(np + 1);
698 np->n_addrlen = dstaddr->sa_len;
699 np->n_name = np->n_addrlen + (char *)np->n_addr;
700 memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen);
701 memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen);
702 if (multicast_mode == PER_INTERFACE_MULTICAST &&
703 (flags & IFF_MULTICAST) &&
704 !(flags & IFF_LOOPBACK)) {
707 memcpy((char *)np->n_addr, (char *)ifaddr,
709 mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP);
710 mreq.imr_interface.s_addr =
711 ((struct sockaddr_in *)np->n_addr)->sin_addr.s_addr;
712 if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP,
713 &mreq, sizeof(mreq)) < 0) {
715 "setsockopt IP_ADD_MEMBERSHIP: %m");
717 /* Fall back to broadcast on this if. */
718 np->n_flags &= ~IFF_MULTICAST;
725 np->n_next = neighbors;
734 Sendto(int s_debug, const void *buf, size_t cc, int flags,
735 const struct sockaddr *to, int tolen)
737 const struct whod *w = (const struct whod *)buf;
738 const struct whoent *we;
739 const struct sockaddr_in *sock_in = (const struct sockaddr_in *)to;
743 ret = sendto(s_debug, buf, cc, flags, to, tolen);
745 printf("sendto %s:%d\n", inet_ntoa(sock_in->sin_addr),
746 ntohs(sock_in->sin_port));
747 printf("hostname %s %s\n", w->wd_hostname,
748 interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), " up"));
749 printf("load %4.2f, %4.2f, %4.2f\n",
750 ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0,
751 ntohl(w->wd_loadav[2]) / 100.0);
753 for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0; cc--, we++) {
754 time_t t = ntohl(we->we_utmp.out_time);
755 idle_time = we->we_idle;
756 printf("%-8.8s %s:%s %.12s",
757 we->we_utmp.out_name,
758 w->wd_hostname, we->we_utmp.out_line,
760 idle_time = ntohl(we->we_idle) / 60;
762 if (idle_time >= 100*60)
763 idle_time = 100*60 - 1;
765 printf(" %2d", idle_time / 60);
768 printf(":%02d", idle_time % 60);
776 interval(int inter_time, const char *updown)
778 static char resbuf[32];
779 int days, hours, minutes;
781 if (inter_time < 0 || inter_time > 3*30*24*60*60) {
782 snprintf(resbuf, sizeof(resbuf), " %s ??:??", updown);
785 minutes = (inter_time + 59) / 60; /* round to minutes */
786 hours = minutes / 60; minutes %= 60;
787 days = hours / 24; hours %= 24;
789 snprintf(resbuf, sizeof(resbuf), "%s %2d+%02d:%02d",
790 updown, days, hours, minutes);
792 snprintf(resbuf, sizeof(resbuf), "%s %2d:%02d",
793 updown, hours, minutes);