1/*	$NetBSD: dm.c,v 1.28 2009/08/12 05:51:59 dholland Exp $	*/
2
3/*
4 * Copyright (c) 1987, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#ifndef lint
34__COPYRIGHT("@(#) Copyright (c) 1987, 1993\
35 The Regents of the University of California.  All rights reserved.");
36#endif /* not lint */
37
38#ifndef lint
39#if 0
40static char sccsid[] = "@(#)dm.c	8.1 (Berkeley) 5/31/93";
41#else
42__RCSID("$NetBSD: dm.c,v 1.28 2009/08/12 05:51:59 dholland Exp $");
43#endif
44#endif /* not lint */
45
46#include <sys/param.h>
47#include <sys/file.h>
48#include <sys/time.h>
49#include <sys/resource.h>
50
51#include <err.h>
52#include <ctype.h>
53#include <errno.h>
54#include <pwd.h>
55#include <stdio.h>
56#include <stdlib.h>
57#include <string.h>
58#include <time.h>
59#include <unistd.h>
60
61#include "utmpentry.h"
62#include "pathnames.h"
63
64static time_t	now;			/* current time value */
65static int	priority = 0;		/* priority game runs at */
66static char	*game,			/* requested game */
67		*gametty;		/* from tty? */
68
69static void c_day(const char *, const char *, const char *);
70static void c_game(const char *, const char  *, const char *, const char *);
71static void c_tty(const char *);
72static const char *hour(int);
73static double load(void);
74static void nogamefile(void);
75static void play(char **) __dead;
76static void read_config(void);
77static int users(void);
78
79#ifdef LOG
80static void logfile(void);
81#endif
82
83int
84main(int argc __unused, char *argv[])
85{
86	char *cp;
87
88	nogamefile();
89	game = (cp = strrchr(*argv, '/')) ? ++cp : *argv;
90
91	if (!strcmp(game, "dm"))
92		exit(0);
93
94	gametty = ttyname(0);
95	unsetenv("TZ");
96	(void)time(&now);
97	read_config();
98#ifdef LOG
99	logfile();
100#endif
101	play(argv);
102	/*NOTREACHED*/
103	return (0);
104}
105
106/*
107 * play --
108 *	play the game
109 */
110static void
111play(char **args)
112{
113	char pbuf[MAXPATHLEN];
114
115	snprintf(pbuf, sizeof(pbuf), "%s%s", _PATH_HIDE, game);
116	if (priority > 0)	/* < 0 requires root */
117		(void)setpriority(PRIO_PROCESS, 0, priority);
118	execv(pbuf, args);
119	err(1, "%s", pbuf);
120}
121
122/*
123 * read_config --
124 *	read through config file, looking for key words.
125 */
126static void
127read_config(void)
128{
129	FILE *cfp;
130	char lbuf[BUFSIZ], f1[40], f2[40], f3[40], f4[40], f5[40];
131
132	if (!(cfp = fopen(_PATH_CONFIG, "r")))
133		return;
134	while (fgets(lbuf, sizeof(lbuf), cfp))
135		switch (*lbuf) {
136		case 'b':		/* badtty */
137			if (sscanf(lbuf, "%39s%39s", f1, f2) != 2 ||
138			    strcasecmp(f1, "badtty"))
139				break;
140			c_tty(f2);
141			break;
142		case 'g':		/* game */
143			if (sscanf(lbuf, "%39s%39s%39s%39s%39s",
144			    f1, f2, f3, f4, f5) != 5 || strcasecmp(f1, "game"))
145				break;
146			c_game(f2, f3, f4, f5);
147			break;
148		case 't':		/* time */
149			if (sscanf(lbuf, "%39s%39s%39s%39s", f1, f2, f3, f4) != 4 ||
150			    strcasecmp(f1, "time"))
151				break;
152			c_day(f2, f3, f4);
153		}
154	(void)fclose(cfp);
155}
156
157/*
158 * c_day --
159 *	if day is today, see if okay to play
160 */
161static void
162c_day(const char *s_day, const char *s_start, const char *s_stop)
163{
164	static const char *const days[] = {
165		"sunday", "monday", "tuesday", "wednesday",
166		"thursday", "friday", "saturday",
167	};
168	static struct tm *ct;
169	int start, stop;
170
171	if (!ct)
172		ct = localtime(&now);
173	if (strcasecmp(s_day, days[ct->tm_wday]))
174		return;
175	if (!isdigit((unsigned char)*s_start) ||
176	    !isdigit((unsigned char)*s_stop))
177		return;
178	start = atoi(s_start);
179	stop = atoi(s_stop);
180	if (ct->tm_hour >= start && ct->tm_hour < stop) {
181		if (start == 0 && stop == 24)
182			errx(0, "Sorry, games are not available today.");
183		else
184			errx(0, "Sorry, games are not available from %s to %s today.",
185			     hour(start), hour(stop));
186	}
187}
188
189/*
190 * c_tty --
191 *	decide if this tty can be used for games.
192 */
193static void
194c_tty(const char *tty)
195{
196	static int first = 1;
197	static char *p_tty;
198
199	if (first) {
200		p_tty = strrchr(gametty, '/');
201		first = 0;
202	}
203
204	if (!strcmp(gametty, tty) || (p_tty && !strcmp(p_tty, tty)))
205		errx(1, "Sorry, you may not play games on %s.", gametty);
206}
207
208/*
209 * c_game --
210 *	see if game can be played now.
211 */
212static void
213c_game(const char *s_game, const char *s_load, const char *s_users,
214       const char *s_priority)
215{
216	static int found;
217
218	if (found)
219		return;
220	if (strcmp(game, s_game) && strcasecmp("default", s_game))
221		return;
222	++found;
223	if (isdigit((unsigned char)*s_load) && atoi(s_load) < load())
224		errx(0, "Sorry, the load average is too high right now.");
225	if (isdigit((unsigned char)*s_users) && atoi(s_users) <= users())
226		errx(0, "Sorry, there are too many users logged on right now.");
227	if (isdigit((unsigned char)*s_priority))
228		priority = atoi(s_priority);
229}
230
231/*
232 * load --
233 *	return 15 minute load average
234 */
235static double
236load(void)
237{
238	double avenrun[3];
239
240	if (getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0])) < 0)
241		err(1, "getloadavg() failed");
242	return (avenrun[2]);
243}
244
245/*
246 * users --
247 *	return current number of users
248 *	todo: check idle time; if idle more than X minutes, don't
249 *	count them.
250 */
251static int
252users(void)
253{
254	struct utmpentry *ep;
255	int nusers;
256
257	nusers = getutentries(NULL, &ep);
258	return nusers;
259}
260
261static void
262nogamefile(void)
263{
264	int fd, n;
265	char buf[BUFSIZ];
266
267	if ((fd = open(_PATH_NOGAMES, O_RDONLY, 0)) >= 0) {
268#define	MESG	"Sorry, no games right now.\n\n"
269		(void)write(2, MESG, sizeof(MESG) - 1);
270		while ((n = read(fd, buf, sizeof(buf))) > 0)
271			(void)write(2, buf, n);
272		exit(1);
273	}
274}
275
276/*
277 * hour --
278 *	print out the hour in human form
279 */
280static const char *
281hour(int h)
282{
283	static const char *const hours[] = {
284	    "midnight", "1am", "2am", "3am", "4am", "5am",
285	    "6am", "7am", "8am", "9am", "10am", "11am",
286	    "noon", "1pm", "2pm", "3pm", "4pm", "5pm",
287	    "6pm", "7pm", "8pm", "9pm", "10pm", "11pm", "midnight" };
288
289	if (h < 0 || h > 24)
290		return ("BAD TIME");
291	else
292		return (hours[h]);
293}
294
295#ifdef LOG
296/*
297 * logfile --
298 *	log play of game
299 */
300static void
301logfile(void)
302{
303	struct passwd *pw;
304	FILE *lp;
305	uid_t uid;
306	int lock_cnt;
307
308	if (lp = fopen(_PATH_LOG, "a")) {
309		for (lock_cnt = 0;; ++lock_cnt) {
310			if (!flock(fileno(lp), LOCK_EX))
311				break;
312			if (lock_cnt == 4) {
313				warnx("log lock");
314				(void)fclose(lp);
315				return;
316			}
317			sleep(1);
318		}
319		if (pw = getpwuid(uid = getuid()))
320			fputs(pw->pw_name, lp);
321		else
322			fprintf(lp, "%u", uid);
323		fprintf(lp, "\t%s\t%s\t%s", game, gametty, ctime(&now));
324		(void)flock(fileno(lp), LOCK_UN);
325		(void)fclose(lp);
326	}
327}
328#endif /* LOG */
329