xref: /netbsd-src/games/dm/dm.c (revision ce666bb8ce77792a3948ca697c2fdad578a542a7)
1 /*	$NetBSD: dm.c,v 1.22 2005/07/02 08:35:29 jmc 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\n\
35 	The Regents of the University of California.  All rights reserved.\n");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)dm.c	8.1 (Berkeley) 5/31/93";
41 #else
42 __RCSID("$NetBSD: dm.c,v 1.22 2005/07/02 08:35:29 jmc 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 
64 static time_t	now;			/* current time value */
65 static int	priority = 0;		/* priority game runs at */
66 static char	*game,			/* requested game */
67 		*gametty;		/* from tty? */
68 
69 void	c_day(const char *, const char *, const char *);
70 void	c_game(const char *, const char  *, const char *, const char *);
71 void	c_tty(const char *);
72 const char *hour(int);
73 double	load(void);
74 void	nogamefile(void);
75 void	play(char **) __attribute__((__noreturn__));
76 void	read_config(void);
77 int	users(void);
78 
79 int
80 main(int argc __attribute__((__unused__)), char *argv[])
81 {
82 	char *cp;
83 
84 	nogamefile();
85 	game = (cp = strrchr(*argv, '/')) ? ++cp : *argv;
86 
87 	if (!strcmp(game, "dm"))
88 		exit(0);
89 
90 	gametty = ttyname(0);
91 	unsetenv("TZ");
92 	(void)time(&now);
93 	read_config();
94 #ifdef LOG
95 	logfile();
96 #endif
97 	play(argv);
98 	/*NOTREACHED*/
99 	return (0);
100 }
101 
102 /*
103  * play --
104  *	play the game
105  */
106 void
107 play(char **args)
108 {
109 	char pbuf[MAXPATHLEN];
110 
111 	snprintf(pbuf, sizeof(pbuf), "%s%s", _PATH_HIDE, game);
112 	if (priority > 0)	/* < 0 requires root */
113 		(void)setpriority(PRIO_PROCESS, 0, priority);
114 	execv(pbuf, args);
115 	err(1, "%s", pbuf);
116 }
117 
118 /*
119  * read_config --
120  *	read through config file, looking for key words.
121  */
122 void
123 read_config(void)
124 {
125 	FILE *cfp;
126 	char lbuf[BUFSIZ], f1[40], f2[40], f3[40], f4[40], f5[40];
127 
128 	if (!(cfp = fopen(_PATH_CONFIG, "r")))
129 		return;
130 	while (fgets(lbuf, sizeof(lbuf), cfp))
131 		switch (*lbuf) {
132 		case 'b':		/* badtty */
133 			if (sscanf(lbuf, "%s%s", f1, f2) != 2 ||
134 			    strcasecmp(f1, "badtty"))
135 				break;
136 			c_tty(f2);
137 			break;
138 		case 'g':		/* game */
139 			if (sscanf(lbuf, "%s%s%s%s%s",
140 			    f1, f2, f3, f4, f5) != 5 || strcasecmp(f1, "game"))
141 				break;
142 			c_game(f2, f3, f4, f5);
143 			break;
144 		case 't':		/* time */
145 			if (sscanf(lbuf, "%s%s%s%s", f1, f2, f3, f4) != 4 ||
146 			    strcasecmp(f1, "time"))
147 				break;
148 			c_day(f2, f3, f4);
149 		}
150 	(void)fclose(cfp);
151 }
152 
153 /*
154  * c_day --
155  *	if day is today, see if okay to play
156  */
157 void
158 c_day(const char *s_day, const char *s_start, const char *s_stop)
159 {
160 	static const char *const days[] = {
161 		"sunday", "monday", "tuesday", "wednesday",
162 		"thursday", "friday", "saturday",
163 	};
164 	static struct tm *ct;
165 	int start, stop;
166 
167 	if (!ct)
168 		ct = localtime(&now);
169 	if (strcasecmp(s_day, days[ct->tm_wday]))
170 		return;
171 	if (!isdigit((unsigned char)*s_start) ||
172 	    !isdigit((unsigned char)*s_stop))
173 		return;
174 	start = atoi(s_start);
175 	stop = atoi(s_stop);
176 	if (ct->tm_hour >= start && ct->tm_hour < stop) {
177 		if (start == 0 && stop == 24)
178 			errx(0, "Sorry, games are not available today.");
179 		else
180 			errx(0, "Sorry, games are not available from %s to %s today.",
181 			     hour(start), hour(stop));
182 	}
183 }
184 
185 /*
186  * c_tty --
187  *	decide if this tty can be used for games.
188  */
189 void
190 c_tty(const char *tty)
191 {
192 	static int first = 1;
193 	static char *p_tty;
194 
195 	if (first) {
196 		p_tty = strrchr(gametty, '/');
197 		first = 0;
198 	}
199 
200 	if (!strcmp(gametty, tty) || (p_tty && !strcmp(p_tty, tty)))
201 		errx(1, "Sorry, you may not play games on %s.", gametty);
202 }
203 
204 /*
205  * c_game --
206  *	see if game can be played now.
207  */
208 void
209 c_game(const char *s_game, const char *s_load, const char *s_users,
210        const char *s_priority)
211 {
212 	static int found;
213 
214 	if (found)
215 		return;
216 	if (strcmp(game, s_game) && strcasecmp("default", s_game))
217 		return;
218 	++found;
219 	if (isdigit((unsigned char)*s_load) && atoi(s_load) < load())
220 		errx(0, "Sorry, the load average is too high right now.");
221 	if (isdigit((unsigned char)*s_users) && atoi(s_users) <= users())
222 		errx(0, "Sorry, there are too many users logged on right now.");
223 	if (isdigit((unsigned char)*s_priority))
224 		priority = atoi(s_priority);
225 }
226 
227 /*
228  * load --
229  *	return 15 minute load average
230  */
231 double
232 load(void)
233 {
234 	double avenrun[3];
235 
236 	if (getloadavg(avenrun, sizeof(avenrun)/sizeof(avenrun[0])) < 0)
237 		err(1, "getloadavg() failed");
238 	return (avenrun[2]);
239 }
240 
241 /*
242  * users --
243  *	return current number of users
244  *	todo: check idle time; if idle more than X minutes, don't
245  *	count them.
246  */
247 int
248 users(void)
249 {
250 	static struct utmpentry *ohead = NULL;
251 	struct utmpentry *ep;
252 	int nusers;
253 
254 	nusers = getutentries(NULL, &ep);
255 	if (ep != ohead) {
256 		freeutentries(ep);
257 		ohead = ep;
258 	}
259 	return nusers;
260 }
261 
262 void
263 nogamefile(void)
264 {
265 	int fd, n;
266 	char buf[BUFSIZ];
267 
268 	if ((fd = open(_PATH_NOGAMES, O_RDONLY, 0)) >= 0) {
269 #define	MESG	"Sorry, no games right now.\n\n"
270 		(void)write(2, MESG, sizeof(MESG) - 1);
271 		while ((n = read(fd, buf, sizeof(buf))) > 0)
272 			(void)write(2, buf, n);
273 		exit(1);
274 	}
275 }
276 
277 /*
278  * hour --
279  *	print out the hour in human form
280  */
281 const char *
282 hour(int h)
283 {
284 	static const char *const hours[] = {
285 	    "midnight", "1am", "2am", "3am", "4am", "5am",
286 	    "6am", "7am", "8am", "9am", "10am", "11am",
287 	    "noon", "1pm", "2pm", "3pm", "4pm", "5pm",
288 	    "6pm", "7pm", "8pm", "9pm", "10pm", "11pm", "midnight" };
289 
290 	if (h < 0 || h > 24)
291 		return ("BAD TIME");
292 	else
293 		return (hours[h]);
294 }
295 
296 #ifdef LOG
297 /*
298  * logfile --
299  *	log play of game
300  */
301 logfile(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((u_int)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)fclose(lp);
325 		(void)flock(fileno(lp), LOCK_UN);
326 	}
327 }
328 #endif /* LOG */
329