/* * Copyright (c) 1983, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef lint static const char copyright[] = "@(#) Copyright (c) 1983, 1993\n\ The Regents of the University of California. All rights reserved.\n"; #endif /* not lint */ #ifndef lint #if 0 static char sccsid[] = "@(#)rwhod.c 8.1 (Berkeley) 6/6/93"; #endif static const char rcsid[] = "$FreeBSD$"; #endif /* not lint */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * This version of Berkeley's rwhod has been modified to use IP multicast * datagrams, under control of a new command-line option: * * rwhod -m causes rwhod to use IP multicast (instead of * broadcast or unicast) on all interfaces that have * the IFF_MULTICAST flag set in their "ifnet" structs * (excluding the loopback interface). The multicast * reports are sent with a time-to-live of 1, to prevent * forwarding beyond the directly-connected subnet(s). * * rwhod -m causes rwhod to send IP multicast datagrams with a * time-to-live of , via a SINGLE interface rather * than all interfaces. must be between 0 and * MAX_MULTICAST_SCOPE, defined below. Note that "-m 1" * is different than "-m", in that "-m 1" specifies * transmission on one interface only. * * When "-m" is used without a argument, the program accepts multicast * rwhod reports from all multicast-capable interfaces. If a argument * is given, it accepts multicast reports from only one interface, the one * on which reports are sent (which may be controlled via the host's routing * table). Regardless of the "-m" option, the program accepts broadcast or * unicast reports from all interfaces. Thus, this program will hear the * reports of old, non-multicasting rwhods, but, if multicasting is used, * those old rwhods won't hear the reports generated by this program. * * -- Steve Deering, Stanford University, February 1989 */ #define UNPRIV_USER "daemon" #define UNPRIV_GROUP "daemon" #define NO_MULTICAST 0 /* multicast modes */ #define PER_INTERFACE_MULTICAST 1 #define SCOPED_MULTICAST 2 #define MAX_MULTICAST_SCOPE 32 /* "site-wide", by convention */ #define INADDR_WHOD_GROUP (u_long)0xe0000103 /* 224.0.1.3 */ /* (belongs in protocols/rwhod.h) */ int insecure_mode; int quiet_mode; int iff_flag = IFF_POINTOPOINT; int multicast_mode = NO_MULTICAST; int multicast_scope; struct sockaddr_in multicast_addr = { sizeof multicast_addr, AF_INET }; /* * Alarm interval. Don't forget to change the down time check in ruptime * if this is changed. */ #define AL_INTERVAL (3 * 60) char myname[MAXHOSTNAMELEN]; /* * We communicate with each neighbor in a list constructed at the time we're * started up. Neighbors are currently directly connected via a hardware * interface. */ struct neighbor { struct neighbor *n_next; char *n_name; /* interface name */ struct sockaddr *n_addr; /* who to send to */ int n_addrlen; /* size of address */ int n_flags; /* should forward?, interface flags */ }; struct neighbor *neighbors; struct whod mywd; struct servent *sp; int s, utmpf; #define WHDRSIZE (sizeof(mywd) - sizeof(mywd.wd_we)) void run_as __P((uid_t *, gid_t *)); int configure __P((int)); void getboottime __P((int)); void onalrm __P((int)); void quit __P((char *)); void rt_xaddrs __P((caddr_t, caddr_t, struct rt_addrinfo *)); int verify __P((char *, int)); static void usage __P((void)); #ifdef DEBUG char *interval __P((int, char *)); void Sendto __P((int, const void *, size_t, int, const struct sockaddr *, int)); #define sendto Sendto #endif int main(argc, argv) int argc; char *argv[]; { struct sockaddr_in from; struct stat st; char path[64]; int on = 1; char *cp; struct sockaddr_in sin; uid_t unpriv_uid; gid_t unpriv_gid; if (getuid()) errx(1, "not super user"); run_as(&unpriv_uid, &unpriv_gid); argv++; argc--; while (argc > 0 && *argv[0] == '-') { if (strcmp(*argv, "-m") == 0) { if (argc > 1 && isdigit(*(argv + 1)[0])) { argv++, argc--; multicast_mode = SCOPED_MULTICAST; multicast_scope = atoi(*argv); if (multicast_scope > MAX_MULTICAST_SCOPE) errx(1, "ttl must not exceed %u", MAX_MULTICAST_SCOPE); } else multicast_mode = PER_INTERFACE_MULTICAST; } else if (strcmp(*argv, "-i") == 0) insecure_mode = 1; else if (strcmp(*argv, "-l") == 0) quiet_mode = 1; else if (strcmp(*argv, "-p") == 0) iff_flag = 0; else usage(); argv++, argc--; } if (argc > 0) usage(); #ifndef DEBUG daemon(1, 0); #endif (void) signal(SIGHUP, getboottime); openlog("rwhod", LOG_PID, LOG_DAEMON); sp = getservbyname("who", "udp"); if (sp == NULL) { syslog(LOG_ERR, "udp/who: unknown service"); exit(1); } if (chdir(_PATH_RWHODIR) < 0) { syslog(LOG_ERR, "%s: %m", _PATH_RWHODIR); exit(1); } /* * Establish host name as returned by system. */ if (gethostname(myname, sizeof(myname) - 1) < 0) { syslog(LOG_ERR, "gethostname: %m"); exit(1); } if ((cp = index(myname, '.')) != NULL) *cp = '\0'; strncpy(mywd.wd_hostname, myname, sizeof(mywd.wd_hostname) - 1); mywd.wd_hostname[sizeof(mywd.wd_hostname) - 1] = '\0'; utmpf = open(_PATH_UTMP, O_RDONLY|O_CREAT, 0644); if (utmpf < 0) { syslog(LOG_ERR, "%s: %m", _PATH_UTMP); exit(1); } getboottime(0); if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { syslog(LOG_ERR, "socket: %m"); exit(1); } if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof(on)) < 0) { syslog(LOG_ERR, "setsockopt SO_BROADCAST: %m"); exit(1); } memset(&sin, 0, sizeof(sin)); sin.sin_len = sizeof(sin); sin.sin_family = AF_INET; sin.sin_port = sp->s_port; if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) < 0) { syslog(LOG_ERR, "bind: %m"); exit(1); } setgid(unpriv_gid); setgroups(1, &unpriv_gid); /* XXX BOGUS groups[0] = egid */ setuid(unpriv_uid); if (!configure(s)) exit(1); if (!quiet_mode) { signal(SIGALRM, onalrm); onalrm(0); } for (;;) { struct whod wd; int cc, whod, len = sizeof(from); cc = recvfrom(s, (char *)&wd, sizeof(struct whod), 0, (struct sockaddr *)&from, &len); if (cc <= 0) { if (cc < 0 && errno != EINTR) syslog(LOG_WARNING, "recv: %m"); continue; } if (from.sin_port != sp->s_port && !insecure_mode) { syslog(LOG_WARNING, "%d: bad from port", ntohs(from.sin_port)); continue; } if (wd.wd_vers != WHODVERSION) continue; if (wd.wd_type != WHODTYPE_STATUS) continue; if (!verify(wd.wd_hostname, sizeof wd.wd_hostname)) { syslog(LOG_WARNING, "malformed host name from %x", from.sin_addr); continue; } (void) snprintf(path, sizeof path, "whod.%s", wd.wd_hostname); /* * Rather than truncating and growing the file each time, * use ftruncate if size is less than previous size. */ whod = open(path, O_WRONLY | O_CREAT, 0644); if (whod < 0) { syslog(LOG_WARNING, "%s: %m", path); continue; } #if ENDIAN != BIG_ENDIAN { int i, n = (cc - WHDRSIZE)/sizeof(struct whoent); struct whoent *we; /* undo header byte swapping before writing to file */ wd.wd_sendtime = ntohl(wd.wd_sendtime); for (i = 0; i < 3; i++) wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]); wd.wd_boottime = ntohl(wd.wd_boottime); we = wd.wd_we; for (i = 0; i < n; i++) { we->we_idle = ntohl(we->we_idle); we->we_utmp.out_time = ntohl(we->we_utmp.out_time); we++; } } #endif (void) time((time_t *)&wd.wd_recvtime); (void) write(whod, (char *)&wd, cc); if (fstat(whod, &st) < 0 || st.st_size > cc) ftruncate(whod, cc); (void) close(whod); } } static void usage() { fprintf(stderr, "usage: rwhod [-i] [-p] [-l] [-m [ttl]]\n"); exit(1); } void run_as(uid, gid) uid_t *uid; gid_t *gid; { struct passwd *pw; struct group *gr; pw = getpwnam(UNPRIV_USER); if (!pw) { syslog(LOG_ERR, "getpwnam(%s): %m", UNPRIV_USER); exit(1); } *uid = pw->pw_uid; gr = getgrnam(UNPRIV_GROUP); if (!gr) { syslog(LOG_ERR, "getgrnam(%s): %m", UNPRIV_GROUP); exit(1); } *gid = gr->gr_gid; } /* * Check out host name for unprintables * and other funnies before allowing a file * to be created. Sorry, but blanks aren't allowed. */ int verify(name, maxlen) register char *name; register int maxlen; { register int size = 0; while (*name && size < maxlen - 1) { if (!isascii(*name) || !(isalnum(*name) || ispunct(*name))) return (0); name++, size++; } *name = '\0'; return (size > 0); } int utmptime; int utmpent; int utmpsize = 0; struct utmp *utmp; int alarmcount; void onalrm(signo) int signo; { register struct neighbor *np; register struct whoent *we = mywd.wd_we, *wlast; register int i; struct stat stb; double avenrun[3]; time_t now; int cc; now = time(NULL); if (alarmcount % 10 == 0) getboottime(0); alarmcount++; (void) fstat(utmpf, &stb); if ((stb.st_mtime != utmptime) || (stb.st_size > utmpsize)) { utmptime = stb.st_mtime; if (stb.st_size > utmpsize) { utmpsize = stb.st_size + 10 * sizeof(struct utmp); if (utmp) utmp = (struct utmp *)realloc(utmp, utmpsize); else utmp = (struct utmp *)malloc(utmpsize); if (! utmp) { syslog(LOG_WARNING, "malloc failed"); utmpsize = 0; goto done; } } (void) lseek(utmpf, (off_t)0, L_SET); cc = read(utmpf, (char *)utmp, stb.st_size); if (cc < 0) { syslog(LOG_ERR, "read(%s): %m", _PATH_UTMP); goto done; } wlast = &mywd.wd_we[1024 / sizeof(struct whoent) - 1]; utmpent = cc / sizeof(struct utmp); for (i = 0; i < utmpent; i++) if (utmp[i].ut_name[0]) { memcpy(we->we_utmp.out_line, utmp[i].ut_line, sizeof(utmp[i].ut_line)); memcpy(we->we_utmp.out_name, utmp[i].ut_name, sizeof(utmp[i].ut_name)); we->we_utmp.out_time = htonl(utmp[i].ut_time); if (we >= wlast) break; we++; } utmpent = we - mywd.wd_we; } /* * The test on utmpent looks silly---after all, if no one is * logged on, why worry about efficiency?---but is useful on * (e.g.) compute servers. */ if (utmpent && chdir(_PATH_DEV)) { syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV); exit(1); } we = mywd.wd_we; for (i = 0; i < utmpent; i++) { if (stat(we->we_utmp.out_line, &stb) >= 0) we->we_idle = htonl(now - stb.st_atime); we++; } (void)getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0])); for (i = 0; i < 3; i++) mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100)); cc = (char *)we - (char *)&mywd; mywd.wd_sendtime = htonl(time(0)); mywd.wd_vers = WHODVERSION; mywd.wd_type = WHODTYPE_STATUS; if (multicast_mode == SCOPED_MULTICAST) { (void) sendto(s, (char *)&mywd, cc, 0, (struct sockaddr *)&multicast_addr, sizeof(multicast_addr)); } else for (np = neighbors; np != NULL; np = np->n_next) { if (multicast_mode == PER_INTERFACE_MULTICAST && np->n_flags & IFF_MULTICAST) { /* * Select the outgoing interface for the multicast. */ if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF, &(((struct sockaddr_in *)np->n_addr)->sin_addr), sizeof(struct in_addr)) < 0) { syslog(LOG_ERR, "setsockopt IP_MULTICAST_IF: %m"); exit(1); } (void) sendto(s, (char *)&mywd, cc, 0, (struct sockaddr *)&multicast_addr, sizeof(multicast_addr)); } else (void) sendto(s, (char *)&mywd, cc, 0, np->n_addr, np->n_addrlen); } if (utmpent && chdir(_PATH_RWHODIR)) { syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR); exit(1); } done: (void) alarm(AL_INTERVAL); } void getboottime(signo) int signo; { int mib[2]; size_t size; struct timeval tm; mib[0] = CTL_KERN; mib[1] = KERN_BOOTTIME; size = sizeof(tm); if (sysctl(mib, 2, &tm, &size, NULL, 0) == -1) { syslog(LOG_ERR, "cannot get boottime: %m"); exit(1); } mywd.wd_boottime = htonl(tm.tv_sec); } void quit(msg) char *msg; { syslog(LOG_ERR, msg); exit(1); } #define ROUNDUP(a) \ ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) #define ADVANCE(x, n) (x += ROUNDUP((n)->sa_len)) void rt_xaddrs(cp, cplim, rtinfo) register caddr_t cp, cplim; register struct rt_addrinfo *rtinfo; { register struct sockaddr *sa; register int i; memset(rtinfo->rti_info, 0, sizeof(rtinfo->rti_info)); for (i = 0; (i < RTAX_MAX) && (cp < cplim); i++) { if ((rtinfo->rti_addrs & (1 << i)) == 0) continue; rtinfo->rti_info[i] = sa = (struct sockaddr *)cp; ADVANCE(cp, sa); } } /* * Figure out device configuration and select * networks which deserve status information. */ int configure(s) int s; { register struct neighbor *np; register struct if_msghdr *ifm; register struct ifa_msghdr *ifam; struct sockaddr_dl *sdl; size_t needed; int mib[6], flags = 0, len; char *buf, *lim, *next; struct rt_addrinfo info; if (multicast_mode != NO_MULTICAST) { multicast_addr.sin_addr.s_addr = htonl(INADDR_WHOD_GROUP); multicast_addr.sin_port = sp->s_port; } if (multicast_mode == SCOPED_MULTICAST) { struct ip_mreq mreq; unsigned char ttl; mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP); mreq.imr_interface.s_addr = htonl(INADDR_ANY); if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) { syslog(LOG_ERR, "setsockopt IP_ADD_MEMBERSHIP: %m"); return(0); } ttl = multicast_scope; if (setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0) { syslog(LOG_ERR, "setsockopt IP_MULTICAST_TTL: %m"); return(0); } return(1); } mib[0] = CTL_NET; mib[1] = PF_ROUTE; mib[2] = 0; mib[3] = AF_INET; mib[4] = NET_RT_IFLIST; mib[5] = 0; if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) quit("route-sysctl-estimate"); if ((buf = malloc(needed)) == NULL) quit("malloc"); if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) quit("actual retrieval of interface table"); lim = buf + needed; sdl = NULL; /* XXX just to keep gcc -Wall happy */ for (next = buf; next < lim; next += ifm->ifm_msglen) { ifm = (struct if_msghdr *)next; if (ifm->ifm_type == RTM_IFINFO) { sdl = (struct sockaddr_dl *)(ifm + 1); flags = ifm->ifm_flags; continue; } if ((flags & IFF_UP) == 0 || (flags & (((multicast_mode == PER_INTERFACE_MULTICAST) ? IFF_MULTICAST : 0) | IFF_BROADCAST|iff_flag)) == 0) continue; if (ifm->ifm_type != RTM_NEWADDR) quit("out of sync parsing NET_RT_IFLIST"); ifam = (struct ifa_msghdr *)ifm; info.rti_addrs = ifam->ifam_addrs; rt_xaddrs((char *)(ifam + 1), ifam->ifam_msglen + (char *)ifam, &info); /* gag, wish we could get rid of Internet dependencies */ #define dstaddr info.rti_info[RTAX_BRD] #define ifaddr info.rti_info[RTAX_IFA] #define IPADDR_SA(x) ((struct sockaddr_in *)(x))->sin_addr.s_addr #define PORT_SA(x) ((struct sockaddr_in *)(x))->sin_port if (dstaddr == 0 || dstaddr->sa_family != AF_INET) continue; PORT_SA(dstaddr) = sp->s_port; for (np = neighbors; np != NULL; np = np->n_next) if (memcmp(sdl->sdl_data, np->n_name, sdl->sdl_nlen) == 0 && IPADDR_SA(np->n_addr) == IPADDR_SA(dstaddr)) break; if (np != NULL) continue; len = sizeof(*np) + dstaddr->sa_len + sdl->sdl_nlen + 1; np = (struct neighbor *)malloc(len); if (np == NULL) quit("malloc of neighbor structure"); memset(np, 0, len); np->n_flags = flags; np->n_addr = (struct sockaddr *)(np + 1); np->n_addrlen = dstaddr->sa_len; np->n_name = np->n_addrlen + (char *)np->n_addr; memcpy((char *)np->n_addr, (char *)dstaddr, np->n_addrlen); memcpy(np->n_name, sdl->sdl_data, sdl->sdl_nlen); if (multicast_mode == PER_INTERFACE_MULTICAST && (flags & IFF_MULTICAST) && !(flags & IFF_LOOPBACK)) { struct ip_mreq mreq; memcpy((char *)np->n_addr, (char *)ifaddr, np->n_addrlen); mreq.imr_multiaddr.s_addr = htonl(INADDR_WHOD_GROUP); mreq.imr_interface.s_addr = ((struct sockaddr_in *)np->n_addr)->sin_addr.s_addr; if (setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) { syslog(LOG_ERR, "setsockopt IP_ADD_MEMBERSHIP: %m"); #if 0 /* Fall back to broadcast on this if. */ np->n_flags &= ~IFF_MULTICAST; #else free((char *)np); continue; #endif } } np->n_next = neighbors; neighbors = np; } free(buf); return (1); } #ifdef DEBUG void Sendto(s, buf, cc, flags, to, tolen) int s; const void *buf; size_t cc; int flags; const struct sockaddr *to; int tolen; { register struct whod *w = (struct whod *)buf; register struct whoent *we; struct sockaddr_in *sin = (struct sockaddr_in *)to; printf("sendto %x.%d\n", ntohl(sin->sin_addr.s_addr), ntohs(sin->sin_port)); printf("hostname %s %s\n", w->wd_hostname, interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), " up")); printf("load %4.2f, %4.2f, %4.2f\n", ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0, ntohl(w->wd_loadav[2]) / 100.0); cc -= WHDRSIZE; for (we = w->wd_we, cc /= sizeof(struct whoent); cc > 0; cc--, we++) { time_t t = ntohl(we->we_utmp.out_time); printf("%-8.8s %s:%s %.12s", we->we_utmp.out_name, w->wd_hostname, we->we_utmp.out_line, ctime(&t)+4); we->we_idle = ntohl(we->we_idle) / 60; if (we->we_idle) { if (we->we_idle >= 100*60) we->we_idle = 100*60 - 1; if (we->we_idle >= 60) printf(" %2d", we->we_idle / 60); else printf(" "); printf(":%02d", we->we_idle % 60); } printf("\n"); } } char * interval(time, updown) int time; char *updown; { static char resbuf[32]; int days, hours, minutes; if (time < 0 || time > 3*30*24*60*60) { (void) sprintf(resbuf, " %s ??:??", updown); return (resbuf); } minutes = (time + 59) / 60; /* round to minutes */ hours = minutes / 60; minutes %= 60; days = hours / 24; hours %= 24; if (days) (void) sprintf(resbuf, "%s %2d+%02d:%02d", updown, days, hours, minutes); else (void) sprintf(resbuf, "%s %2d:%02d", updown, hours, minutes); return (resbuf); } #endif