xref: /netbsd/games/dm/dm.c (revision bf9ec67e)
1 /*	$NetBSD: dm.c,v 1.16 2001/01/25 20:41:41 jdolecek 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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include <sys/cdefs.h>
37 #ifndef lint
38 __COPYRIGHT("@(#) Copyright (c) 1987, 1993\n\
39 	The Regents of the University of California.  All rights reserved.\n");
40 #endif /* not lint */
41 
42 #ifndef lint
43 #if 0
44 static char sccsid[] = "@(#)dm.c	8.1 (Berkeley) 5/31/93";
45 #else
46 __RCSID("$NetBSD: dm.c,v 1.16 2001/01/25 20:41:41 jdolecek Exp $");
47 #endif
48 #endif /* not lint */
49 
50 #include <sys/param.h>
51 #include <sys/file.h>
52 #include <sys/time.h>
53 #include <sys/resource.h>
54 
55 #include <err.h>
56 #include <ctype.h>
57 #include <errno.h>
58 #include <pwd.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <time.h>
63 #include <unistd.h>
64 #include <utmp.h>
65 
66 #include "pathnames.h"
67 
68 static time_t	now;			/* current time value */
69 static int	priority = 0;		/* priority game runs at */
70 static char	*game,			/* requested game */
71 		*gametty;		/* from tty? */
72 
73 void	c_day __P((const char *, const char *, const char *));
74 void	c_game __P((const char *, const char  *, const char *, const char *));
75 void	c_tty __P((const char *));
76 const char *hour __P((int));
77 double	load __P((void));
78 int	main __P((int, char *[]));
79 void	nogamefile __P((void));
80 void	play __P((char **)) __attribute__((__noreturn__));
81 void	read_config __P((void));
82 int	users __P((void));
83 
84 int
85 main(argc, argv)
86 	int argc;
87 	char *argv[];
88 {
89 	char *cp;
90 
91 	nogamefile();
92 	game = (cp = strrchr(*argv, '/')) ? ++cp : *argv;
93 
94 	if (!strcmp(game, "dm"))
95 		exit(0);
96 
97 	gametty = ttyname(0);
98 	unsetenv("TZ");
99 	(void)time(&now);
100 	read_config();
101 #ifdef LOG
102 	logfile();
103 #endif
104 	play(argv);
105 	/*NOTREACHED*/
106 	return (0);
107 }
108 
109 /*
110  * play --
111  *	play the game
112  */
113 void
114 play(args)
115 	char **args;
116 {
117 	char pbuf[MAXPATHLEN];
118 
119 	snprintf(pbuf, sizeof(pbuf), "%s%s", _PATH_HIDE, game);
120 	if (priority > 0)	/* < 0 requires root */
121 		(void)setpriority(PRIO_PROCESS, 0, priority);
122 	execv(pbuf, args);
123 	err(1, "%s", pbuf);
124 }
125 
126 /*
127  * read_config --
128  *	read through config file, looking for key words.
129  */
130 void
131 read_config()
132 {
133 	FILE *cfp;
134 	char lbuf[BUFSIZ], f1[40], f2[40], f3[40], f4[40], f5[40];
135 
136 	if (!(cfp = fopen(_PATH_CONFIG, "r")))
137 		return;
138 	while (fgets(lbuf, sizeof(lbuf), cfp))
139 		switch (*lbuf) {
140 		case 'b':		/* badtty */
141 			if (sscanf(lbuf, "%s%s", f1, f2) != 2 ||
142 			    strcasecmp(f1, "badtty"))
143 				break;
144 			c_tty(f2);
145 			break;
146 		case 'g':		/* game */
147 			if (sscanf(lbuf, "%s%s%s%s%s",
148 			    f1, f2, f3, f4, f5) != 5 || strcasecmp(f1, "game"))
149 				break;
150 			c_game(f2, f3, f4, f5);
151 			break;
152 		case 't':		/* time */
153 			if (sscanf(lbuf, "%s%s%s%s", f1, f2, f3, f4) != 4 ||
154 			    strcasecmp(f1, "time"))
155 				break;
156 			c_day(f2, f3, f4);
157 		}
158 	(void)fclose(cfp);
159 }
160 
161 /*
162  * c_day --
163  *	if day is today, see if okay to play
164  */
165 void
166 c_day(s_day, s_start, s_stop)
167 	const char *s_day, *s_start, *s_stop;
168 {
169 	static const char *const days[] = {
170 		"sunday", "monday", "tuesday", "wednesday",
171 		"thursday", "friday", "saturday",
172 	};
173 	static struct tm *ct;
174 	int start, stop;
175 
176 	if (!ct)
177 		ct = localtime(&now);
178 	if (strcasecmp(s_day, days[ct->tm_wday]))
179 		return;
180 	if (!isdigit(*s_start) || !isdigit(*s_stop))
181 		return;
182 	start = atoi(s_start);
183 	stop = atoi(s_stop);
184 	if (ct->tm_hour >= start && ct->tm_hour < stop) {
185 		if (start == 0 && stop == 24)
186 			errx(0, "Sorry, games are not available today.");
187 		else
188 			errx(0, "Sorry, games are not available from %s to %s today.",
189 			     hour(start), hour(stop));
190 	}
191 }
192 
193 /*
194  * c_tty --
195  *	decide if this tty can be used for games.
196  */
197 void
198 c_tty(tty)
199 	const char *tty;
200 {
201 	static int first = 1;
202 	static char *p_tty;
203 
204 	if (first) {
205 		p_tty = strrchr(gametty, '/');
206 		first = 0;
207 	}
208 
209 	if (!strcmp(gametty, tty) || (p_tty && !strcmp(p_tty, tty)))
210 		errx(1, "Sorry, you may not play games on %s.", gametty);
211 }
212 
213 /*
214  * c_game --
215  *	see if game can be played now.
216  */
217 void
218 c_game(s_game, s_load, s_users, s_priority)
219 	const char *s_game, *s_load, *s_users, *s_priority;
220 {
221 	static int found;
222 
223 	if (found)
224 		return;
225 	if (strcmp(game, s_game) && strcasecmp("default", s_game))
226 		return;
227 	++found;
228 	if (isdigit(*s_load) && atoi(s_load) < load())
229 		errx(0, "Sorry, the load average is too high right now.");
230 	if (isdigit(*s_users) && atoi(s_users) <= users())
231 		errx(0, "Sorry, there are too many users logged on right now.");
232 	if (isdigit(*s_priority))
233 		priority = atoi(s_priority);
234 }
235 
236 /*
237  * load --
238  *	return 15 minute load average
239  */
240 double
241 load()
242 {
243 	double avenrun[3];
244 
245 	if (getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0])) < 0)
246 		err(1, "getloadavg() failed");
247 	return (avenrun[2]);
248 }
249 
250 /*
251  * users --
252  *	return current number of users
253  *	todo: check idle time; if idle more than X minutes, don't
254  *	count them.
255  */
256 int
257 users()
258 {
259 
260 	int nusers, utmp;
261 	struct utmp buf;
262 
263 	if ((utmp = open(_PATH_UTMP, O_RDONLY, 0)) < 0)
264 		err(1, "%s", _PATH_UTMP);
265 	for (nusers = 0; read(utmp, (char *)&buf, sizeof(struct utmp)) > 0;)
266 		if (buf.ut_name[0] != '\0')
267 			++nusers;
268 	return (nusers);
269 }
270 
271 void
272 nogamefile()
273 {
274 	int fd, n;
275 	char buf[BUFSIZ];
276 
277 	if ((fd = open(_PATH_NOGAMES, O_RDONLY, 0)) >= 0) {
278 #define	MESG	"Sorry, no games right now.\n\n"
279 		(void)write(2, MESG, sizeof(MESG) - 1);
280 		while ((n = read(fd, buf, sizeof(buf))) > 0)
281 			(void)write(2, buf, n);
282 		exit(1);
283 	}
284 }
285 
286 /*
287  * hour --
288  *	print out the hour in human form
289  */
290 const char *
291 hour(h)
292 	int h;
293 {
294 	static const char *const hours[] = {
295 	    "midnight", "1am", "2am", "3am", "4am", "5am",
296 	    "6am", "7am", "8am", "9am", "10am", "11am",
297 	    "noon", "1pm", "2pm", "3pm", "4pm", "5pm",
298 	    "6pm", "7pm", "8pm", "9pm", "10pm", "11pm", "midnight" };
299 
300 	if (h < 0 || h > 24)
301 		return ("BAD TIME");
302 	else
303 		return (hours[h]);
304 }
305 
306 #ifdef LOG
307 /*
308  * logfile --
309  *	log play of game
310  */
311 logfile()
312 {
313 	struct passwd *pw;
314 	FILE *lp;
315 	uid_t uid;
316 	int lock_cnt;
317 
318 	if (lp = fopen(_PATH_LOG, "a")) {
319 		for (lock_cnt = 0;; ++lock_cnt) {
320 			if (!flock(fileno(lp), LOCK_EX))
321 				break;
322 			if (lock_cnt == 4) {
323 				warnx("log lock");
324 				(void)fclose(lp);
325 				return;
326 			}
327 			sleep((u_int)1);
328 		}
329 		if (pw = getpwuid(uid = getuid()))
330 			fputs(pw->pw_name, lp);
331 		else
332 			fprintf(lp, "%u", uid);
333 		fprintf(lp, "\t%s\t%s\t%s", game, gametty, ctime(&now));
334 		(void)fclose(lp);
335 		(void)flock(fileno(lp), LOCK_UN);
336 	}
337 }
338 #endif /* LOG */
339