xref: /original-bsd/usr.sbin/rwhod/rwhod.c (revision 4e9331e4)
1 /*
2  * Copyright (c) 1983 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms are permitted
6  * provided that the above copyright notice and this paragraph are
7  * duplicated in all such forms and that any documentation,
8  * advertising materials, and other materials related to such
9  * distribution and use acknowledge that the software was developed
10  * by the University of California, Berkeley.  The name of the
11  * University may not be used to endorse or promote products derived
12  * from this software without specific prior written permission.
13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
15  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
16  */
17 
18 #ifndef lint
19 char copyright[] =
20 "@(#) Copyright (c) 1983 The Regents of the University of California.\n\
21  All rights reserved.\n";
22 #endif /* not lint */
23 
24 #ifndef lint
25 static char sccsid[] = "@(#)rwhod.c	5.14 (Berkeley) 05/29/89";
26 #endif /* not lint */
27 
28 #include <sys/types.h>
29 #include <sys/socket.h>
30 #include <sys/stat.h>
31 #include <sys/signal.h>
32 #include <sys/ioctl.h>
33 #include <sys/file.h>
34 
35 #include <net/if.h>
36 #include <netinet/in.h>
37 
38 #include <nlist.h>
39 #include <errno.h>
40 #include <utmp.h>
41 #include <ctype.h>
42 #include <netdb.h>
43 #include <syslog.h>
44 #include <protocols/rwhod.h>
45 #include <stdio.h>
46 #include <paths.h>
47 
48 /*
49  * Alarm interval. Don't forget to change the down time check in ruptime
50  * if this is changed.
51  */
52 #define AL_INTERVAL (3 * 60)
53 
54 struct	sockaddr_in sin = { AF_INET };
55 
56 char	myname[32];
57 
58 struct	nlist nl[] = {
59 #define	NL_BOOTTIME	0
60 	{ "_boottime" },
61 	0
62 };
63 
64 /*
65  * We communicate with each neighbor in
66  * a list constructed at the time we're
67  * started up.  Neighbors are currently
68  * directly connected via a hardware interface.
69  */
70 struct	neighbor {
71 	struct	neighbor *n_next;
72 	char	*n_name;		/* interface name */
73 	char	*n_addr;		/* who to send to */
74 	int	n_addrlen;		/* size of address */
75 	int	n_flags;		/* should forward?, interface flags */
76 };
77 
78 struct	neighbor *neighbors;
79 struct	whod mywd;
80 struct	servent *sp;
81 int	s, utmpf, kmemf = -1;
82 
83 #define	WHDRSIZE	(sizeof (mywd) - sizeof (mywd.wd_we))
84 
85 extern int errno;
86 int	onalrm();
87 char	*strcpy(), *malloc();
88 long	lseek();
89 int	getkmem();
90 struct	in_addr inet_makeaddr();
91 
92 main()
93 {
94 	struct sockaddr_in from;
95 	struct stat st;
96 	char path[64];
97 	int on = 1;
98 	char *cp, *index(), *strerror();
99 
100 	if (getuid()) {
101 		fprintf(stderr, "rwhod: not super user\n");
102 		exit(1);
103 	}
104 	sp = getservbyname("who", "udp");
105 	if (sp == 0) {
106 		fprintf(stderr, "rwhod: udp/who: unknown service\n");
107 		exit(1);
108 	}
109 #ifndef DEBUG
110 	if (fork())
111 		exit(0);
112 	{ int s;
113 	  for (s = 0; s < 10; s++)
114 		(void) close(s);
115 	  (void) open("/", 0);
116 	  (void) dup2(0, 1);
117 	  (void) dup2(0, 2);
118 	  s = open(_PATH_TTY, 2);
119 	  if (s >= 0) {
120 		ioctl(s, TIOCNOTTY, 0);
121 		(void) close(s);
122 	  }
123 	}
124 #endif
125 	if (chdir(_PATH_RWHODIR) < 0) {
126 		(void)fprintf(stderr, "rwhod: %s: %s\n",
127 		    _PATH_RWHODIR, strerror(errno));
128 		exit(1);
129 	}
130 	(void) signal(SIGHUP, getkmem);
131 	openlog("rwhod", LOG_PID, LOG_DAEMON);
132 	/*
133 	 * Establish host name as returned by system.
134 	 */
135 	if (gethostname(myname, sizeof (myname) - 1) < 0) {
136 		syslog(LOG_ERR, "gethostname: %m");
137 		exit(1);
138 	}
139 	if ((cp = index(myname, '.')) != NULL)
140 		*cp = '\0';
141 	strncpy(mywd.wd_hostname, myname, sizeof (myname) - 1);
142 	utmpf = open(_PATH_UTMP, O_RDONLY|O_CREAT, 0644);
143 	if (utmpf < 0) {
144 		syslog(LOG_ERR, "%s: %m", _PATH_UTMP);
145 		exit(1);
146 	}
147 	getkmem();
148 	if ((s = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
149 		syslog(LOG_ERR, "socket: %m");
150 		exit(1);
151 	}
152 	if (setsockopt(s, SOL_SOCKET, SO_BROADCAST, &on, sizeof (on)) < 0) {
153 		syslog(LOG_ERR, "setsockopt SO_BROADCAST: %m");
154 		exit(1);
155 	}
156 	sin.sin_port = sp->s_port;
157 	if (bind(s, &sin, sizeof (sin)) < 0) {
158 		syslog(LOG_ERR, "bind: %m");
159 		exit(1);
160 	}
161 	if (!configure(s))
162 		exit(1);
163 	signal(SIGALRM, onalrm);
164 	onalrm();
165 	for (;;) {
166 		struct whod wd;
167 		int cc, whod, len = sizeof (from);
168 
169 		cc = recvfrom(s, (char *)&wd, sizeof (struct whod), 0,
170 			&from, &len);
171 		if (cc <= 0) {
172 			if (cc < 0 && errno != EINTR)
173 				syslog(LOG_WARNING, "recv: %m");
174 			continue;
175 		}
176 		if (from.sin_port != sp->s_port) {
177 			syslog(LOG_WARNING, "%d: bad from port",
178 				ntohs(from.sin_port));
179 			continue;
180 		}
181 #ifdef notdef
182 		if (gethostbyname(wd.wd_hostname) == 0) {
183 			syslog(LOG_WARNING, "%s: unknown host",
184 				wd.wd_hostname);
185 			continue;
186 		}
187 #endif
188 		if (wd.wd_vers != WHODVERSION)
189 			continue;
190 		if (wd.wd_type != WHODTYPE_STATUS)
191 			continue;
192 		if (!verify(wd.wd_hostname)) {
193 			syslog(LOG_WARNING, "malformed host name from %x",
194 				from.sin_addr);
195 			continue;
196 		}
197 		(void) sprintf(path, "whod.%s", wd.wd_hostname);
198 		/*
199 		 * Rather than truncating and growing the file each time,
200 		 * use ftruncate if size is less than previous size.
201 		 */
202 		whod = open(path, O_WRONLY | O_CREAT, 0644);
203 		if (whod < 0) {
204 			syslog(LOG_WARNING, "%s: %m", path);
205 			continue;
206 		}
207 #if vax || pdp11
208 		{
209 			int i, n = (cc - WHDRSIZE)/sizeof(struct whoent);
210 			struct whoent *we;
211 
212 			/* undo header byte swapping before writing to file */
213 			wd.wd_sendtime = ntohl(wd.wd_sendtime);
214 			for (i = 0; i < 3; i++)
215 				wd.wd_loadav[i] = ntohl(wd.wd_loadav[i]);
216 			wd.wd_boottime = ntohl(wd.wd_boottime);
217 			we = wd.wd_we;
218 			for (i = 0; i < n; i++) {
219 				we->we_idle = ntohl(we->we_idle);
220 				we->we_utmp.out_time =
221 				    ntohl(we->we_utmp.out_time);
222 				we++;
223 			}
224 		}
225 #endif
226 		(void) time(&wd.wd_recvtime);
227 		(void) write(whod, (char *)&wd, cc);
228 		if (fstat(whod, &st) < 0 || st.st_size > cc)
229 			ftruncate(whod, cc);
230 		(void) close(whod);
231 	}
232 }
233 
234 /*
235  * Check out host name for unprintables
236  * and other funnies before allowing a file
237  * to be created.  Sorry, but blanks aren't allowed.
238  */
239 verify(name)
240 	register char *name;
241 {
242 	register int size = 0;
243 
244 	while (*name) {
245 		if (!isascii(*name) || !(isalnum(*name) || ispunct(*name)))
246 			return (0);
247 		name++, size++;
248 	}
249 	return (size > 0);
250 }
251 
252 int	utmptime;
253 int	utmpent;
254 int	utmpsize = 0;
255 struct	utmp *utmp;
256 int	alarmcount;
257 
258 onalrm()
259 {
260 	register struct neighbor *np;
261 	register struct whoent *we = mywd.wd_we, *wlast;
262 	register int i;
263 	struct stat stb;
264 	int cc;
265 	double avenrun[3];
266 	time_t now = time((time_t *)NULL);
267 	char *strerror();
268 
269 	if (alarmcount % 10 == 0)
270 		getkmem();
271 	alarmcount++;
272 	(void) fstat(utmpf, &stb);
273 	if ((stb.st_mtime != utmptime) || (stb.st_size > utmpsize)) {
274 		utmptime = stb.st_mtime;
275 		if (stb.st_size > utmpsize) {
276 			utmpsize = stb.st_size + 10 * sizeof(struct utmp);
277 			if (utmp)
278 				utmp = (struct utmp *)realloc(utmp, utmpsize);
279 			else
280 				utmp = (struct utmp *)malloc(utmpsize);
281 			if (! utmp) {
282 				fprintf(stderr, "rwhod: malloc failed\n");
283 				utmpsize = 0;
284 				goto done;
285 			}
286 		}
287 		(void) lseek(utmpf, (long)0, L_SET);
288 		cc = read(utmpf, (char *)utmp, stb.st_size);
289 		if (cc < 0) {
290 			fprintf(stderr, "rwhod: %s: %s\n",
291 			    _PATH_UTMP, strerror(errno));
292 			goto done;
293 		}
294 		wlast = &mywd.wd_we[1024 / sizeof (struct whoent) - 1];
295 		utmpent = cc / sizeof (struct utmp);
296 		for (i = 0; i < utmpent; i++)
297 			if (utmp[i].ut_name[0]) {
298 				bcopy(utmp[i].ut_line, we->we_utmp.out_line,
299 				   sizeof (utmp[i].ut_line));
300 				bcopy(utmp[i].ut_name, we->we_utmp.out_name,
301 				   sizeof (utmp[i].ut_name));
302 				we->we_utmp.out_time = htonl(utmp[i].ut_time);
303 				if (we >= wlast)
304 					break;
305 				we++;
306 			}
307 		utmpent = we - mywd.wd_we;
308 	}
309 
310 	/*
311 	 * The test on utmpent looks silly---after all, if no one is
312 	 * logged on, why worry about efficiency?---but is useful on
313 	 * (e.g.) compute servers.
314 	 */
315 	if (utmpent && chdir(_PATH_DEV)) {
316 		syslog(LOG_ERR, "chdir(%s): %m", _PATH_DEV);
317 		exit(1);
318 	}
319 	we = mywd.wd_we;
320 	for (i = 0; i < utmpent; i++) {
321 		if (stat(we->we_utmp.out_line, &stb) >= 0)
322 			we->we_idle = htonl(now - stb.st_atime);
323 		we++;
324 	}
325 	(void) getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0]));
326 	for (i = 0; i < 3; i++)
327 		mywd.wd_loadav[i] = htonl((u_long)(avenrun[i] * 100));
328 	cc = (char *)we - (char *)&mywd;
329 	mywd.wd_sendtime = htonl(time(0));
330 	mywd.wd_vers = WHODVERSION;
331 	mywd.wd_type = WHODTYPE_STATUS;
332 	for (np = neighbors; np != NULL; np = np->n_next)
333 		(void) sendto(s, (char *)&mywd, cc, 0,
334 			np->n_addr, np->n_addrlen);
335 	if (utmpent && chdir(_PATH_RWHODIR)) {
336 		syslog(LOG_ERR, "chdir(%s): %m", _PATH_RWHODIR);
337 		exit(1);
338 	}
339 done:
340 	(void) alarm(AL_INTERVAL);
341 }
342 
343 getkmem()
344 {
345 	static ino_t vmunixino;
346 	static time_t vmunixctime;
347 	struct stat sb;
348 
349 	if (stat(_PATH_UNIX, &sb) < 0) {
350 		if (vmunixctime)
351 			return;
352 	} else {
353 		if (sb.st_ctime == vmunixctime && sb.st_ino == vmunixino)
354 			return;
355 		vmunixctime = sb.st_ctime;
356 		vmunixino= sb.st_ino;
357 	}
358 	if (kmemf >= 0)
359 		(void) close(kmemf);
360 loop:
361 	if (nlist(_PATH_UNIX, nl)) {
362 		syslog(LOG_WARNING, "%s: namelist botch", _PATH_UNIX);
363 		sleep(300);
364 		goto loop;
365 	}
366 	kmemf = open(_PATH_KMEM, O_RDONLY, 0);
367 	if (kmemf < 0) {
368 		syslog(LOG_ERR, "%s: %m", _PATH_KMEM);
369 		exit(1);
370 	}
371 	(void) lseek(kmemf, (long)nl[NL_BOOTTIME].n_value, L_SET);
372 	(void) read(kmemf, (char *)&mywd.wd_boottime,
373 	    sizeof (mywd.wd_boottime));
374 	mywd.wd_boottime = htonl(mywd.wd_boottime);
375 }
376 
377 /*
378  * Figure out device configuration and select
379  * networks which deserve status information.
380  */
381 configure(s)
382 	int s;
383 {
384 	char buf[BUFSIZ];
385 	struct ifconf ifc;
386 	struct ifreq ifreq, *ifr;
387 	struct sockaddr_in *sin;
388 	register struct neighbor *np;
389 	int n;
390 
391 	ifc.ifc_len = sizeof (buf);
392 	ifc.ifc_buf = buf;
393 	if (ioctl(s, SIOCGIFCONF, (char *)&ifc) < 0) {
394 		syslog(LOG_ERR, "ioctl (get interface configuration)");
395 		return (0);
396 	}
397 	ifr = ifc.ifc_req;
398 	for (n = ifc.ifc_len / sizeof (struct ifreq); n > 0; n--, ifr++) {
399 		for (np = neighbors; np != NULL; np = np->n_next)
400 			if (np->n_name &&
401 			    strcmp(ifr->ifr_name, np->n_name) == 0)
402 				break;
403 		if (np != NULL)
404 			continue;
405 		ifreq = *ifr;
406 		np = (struct neighbor *)malloc(sizeof (*np));
407 		if (np == NULL)
408 			continue;
409 		np->n_name = malloc(strlen(ifr->ifr_name) + 1);
410 		if (np->n_name == NULL) {
411 			free((char *)np);
412 			continue;
413 		}
414 		strcpy(np->n_name, ifr->ifr_name);
415 		np->n_addrlen = sizeof (ifr->ifr_addr);
416 		np->n_addr = malloc(np->n_addrlen);
417 		if (np->n_addr == NULL) {
418 			free(np->n_name);
419 			free((char *)np);
420 			continue;
421 		}
422 		bcopy((char *)&ifr->ifr_addr, np->n_addr, np->n_addrlen);
423 		if (ioctl(s, SIOCGIFFLAGS, (char *)&ifreq) < 0) {
424 			syslog(LOG_ERR, "ioctl (get interface flags)");
425 			free((char *)np);
426 			continue;
427 		}
428 		if ((ifreq.ifr_flags & IFF_UP) == 0 ||
429 		    (ifreq.ifr_flags & (IFF_BROADCAST|IFF_POINTOPOINT)) == 0) {
430 			free((char *)np);
431 			continue;
432 		}
433 		np->n_flags = ifreq.ifr_flags;
434 		if (np->n_flags & IFF_POINTOPOINT) {
435 			if (ioctl(s, SIOCGIFDSTADDR, (char *)&ifreq) < 0) {
436 				syslog(LOG_ERR, "ioctl (get dstaddr)");
437 				free((char *)np);
438 				continue;
439 			}
440 			/* we assume addresses are all the same size */
441 			bcopy((char *)&ifreq.ifr_dstaddr,
442 			  np->n_addr, np->n_addrlen);
443 		}
444 		if (np->n_flags & IFF_BROADCAST) {
445 			if (ioctl(s, SIOCGIFBRDADDR, (char *)&ifreq) < 0) {
446 				syslog(LOG_ERR, "ioctl (get broadaddr)");
447 				free((char *)np);
448 				continue;
449 			}
450 			/* we assume addresses are all the same size */
451 			bcopy((char *)&ifreq.ifr_broadaddr,
452 			  np->n_addr, np->n_addrlen);
453 		}
454 		/* gag, wish we could get rid of Internet dependencies */
455 		sin = (struct sockaddr_in *)np->n_addr;
456 		sin->sin_port = sp->s_port;
457 		np->n_next = neighbors;
458 		neighbors = np;
459 	}
460 	return (1);
461 }
462 
463 #ifdef DEBUG
464 sendto(s, buf, cc, flags, to, tolen)
465 	int s;
466 	char *buf;
467 	int cc, flags;
468 	char *to;
469 	int tolen;
470 {
471 	register struct whod *w = (struct whod *)buf;
472 	register struct whoent *we;
473 	struct sockaddr_in *sin = (struct sockaddr_in *)to;
474 	char *interval();
475 
476 	printf("sendto %x.%d\n", ntohl(sin->sin_addr), ntohs(sin->sin_port));
477 	printf("hostname %s %s\n", w->wd_hostname,
478 	   interval(ntohl(w->wd_sendtime) - ntohl(w->wd_boottime), "  up"));
479 	printf("load %4.2f, %4.2f, %4.2f\n",
480 	    ntohl(w->wd_loadav[0]) / 100.0, ntohl(w->wd_loadav[1]) / 100.0,
481 	    ntohl(w->wd_loadav[2]) / 100.0);
482 	cc -= WHDRSIZE;
483 	for (we = w->wd_we, cc /= sizeof (struct whoent); cc > 0; cc--, we++) {
484 		time_t t = ntohl(we->we_utmp.out_time);
485 		printf("%-8.8s %s:%s %.12s",
486 			we->we_utmp.out_name,
487 			w->wd_hostname, we->we_utmp.out_line,
488 			ctime(&t)+4);
489 		we->we_idle = ntohl(we->we_idle) / 60;
490 		if (we->we_idle) {
491 			if (we->we_idle >= 100*60)
492 				we->we_idle = 100*60 - 1;
493 			if (we->we_idle >= 60)
494 				printf(" %2d", we->we_idle / 60);
495 			else
496 				printf("   ");
497 			printf(":%02d", we->we_idle % 60);
498 		}
499 		printf("\n");
500 	}
501 }
502 
503 char *
504 interval(time, updown)
505 	int time;
506 	char *updown;
507 {
508 	static char resbuf[32];
509 	int days, hours, minutes;
510 
511 	if (time < 0 || time > 3*30*24*60*60) {
512 		(void) sprintf(resbuf, "   %s ??:??", updown);
513 		return (resbuf);
514 	}
515 	minutes = (time + 59) / 60;		/* round to minutes */
516 	hours = minutes / 60; minutes %= 60;
517 	days = hours / 24; hours %= 24;
518 	if (days)
519 		(void) sprintf(resbuf, "%s %2d+%02d:%02d",
520 		    updown, days, hours, minutes);
521 	else
522 		(void) sprintf(resbuf, "%s    %2d:%02d",
523 		    updown, hours, minutes);
524 	return (resbuf);
525 }
526 #endif
527